1, 4-Xylene-2, S-diboronic acid (111) was prepared in 44% yield by the reaction of the Grignard reagent from 2, d-dibromo-1, 4-xylene with n-butyl borate; some j-bromo-l, 4-xylene- 2-boronic acid was obtained as a by-product. The diboronic acid closely resembled benzenc- ll4-diboronic acid4 in that it was resistant to dehydration and was readily esterified with S- methyldiethano1amine. j However, unlike the benzene diboronic acid, it could not be ...
